U.S. DEPARTMENT OF JUSTICE
OFFICE OF JUSTICE PROGRAMS
NATIONAL INSTITUTE OF JUSTICE
NATIONAL INSTITUTE OF JUSTICE
RESEARCH IN BRIEF
JANUARY 1993
CHARLES B. DEWITT, DIRECTOR
TESTING HAIR FOR ILLICIT DRUG USE
TOM MIECZKOWSKI
HARVEY J. LANDRESS,
RICHARD NEWEL
SHIRLEY D. COLETTI
[Letter from the Director]
Testing for drug use is an essential element in the Nation's battle against
drug abuse and drug-related crime. The Drug Use Forecasting (DUF) program
established by the National Institute of Justice (NIJ) in 1987 relies upon
urinalysis, a recognized indicator of drug use.
NIJ is seeking alternative techniques with complementary capabilities to
strengthen detection and control of drug use. Hair testing may provide wider
windows of detection and less opportunity for evasion.
Hair analysis offers unique advantages compared to other currently used drug
testing methods. Hair retains drug components for longer periods, and drug
use can be detected in hair for weeks or even months compared to the 2 to 3
days that cocaine or heroin can be detected in blood or urine.
As this Research in Brief points out, hair analysis also offers other
advantages over other testing methods: for example, hair specimens can be
readily obtained without the privacy problems associated with obtaining urine
specimens or the invasiveness of drawing blood.
NIJ is currently conducting research into the effectiveness of the use of
hair analysis, efforts that will explore the cost and operational issues
involved in implementing this drug testing method in probation and parole
settings.
[End Letter]
The rising popularity of cocaine since the mid-1980's gave new urgency to the
longstanding interest in developing accurate ways to measure the incidence
and prevalence of drug use. Accurate estimates of drug trends within an
offender population are critical in the development of public policy and the
efficient use of limited criminal justice resources.
To this end, a National Institute of Justice (NIJ) study among arrestees in
an urban county jail compared tests of hair for signs of drugs of abuse with
testing by urinalysis and with self-reports of drug use. The study also
considered how applicable hair testing might be for monitoring the drug
status of offenders. The study's results are summarized in this Research in
Brief:
Monitoring offenders' drug use
At a variety of criminal justice system levels, monitoring the drug status of
offenders is of considerable importance. Indeed, the use of drug monitoring
to help determine particular criminal dispositions is already established in
many local justice agencies (ref. l) and a person's drug use patterns and
history often inform decisions related to placement, release and
surveillance, and mandatory referral to treatment.
Urinalysis testing
Self-reported drug use has been the most widely used source of drug use data
for the past three decades,(ref. 2) but since the early 1970's and the
development of reliable and inexpensive immunoassay technology, urinalysis
screening has become an important tool. Systems such as NIJ's Drug Use
Forecasting (DUF) program, cofunded by the Bureau of Justice Assistance,
proved the utility of urinalysis in acquiring accurate data among a criminal
justice population.
Immunoassay technology, whether based on radioisotopes, enzymes, or
fluorescence, enhanced our ability to measure illicit drug use. However, use
of urine as the test medium imposes practical limitations on the frequency of
collection when these techniques are applied. Opiates and cocaine are
water-soluble and quite rapidly excreted, generally within 48 to 72 hours.
Only marijuana, which is fat-soluble, has a slow, relatively long-term urine
excretion rate (regular, heavy users can test positive for several weeks).
These characteristics suggest that urine-based data on cocaine and opiate use
derived from a single urine test, underestimate the true extent of opiate and
cocaine use.
Use of hair testing
Use of hair as a test medium avoids the limitations of infrequent urine
testing. Hair testing is relatively well established and uses a number of the
same technologies as urine-based tests, including enzyme, radioisotope, and
fluorescent immunoassays. The methodologies are identical: the distinction is
in
the medium.
Hair has several advantages over urine in testing for drugs of abuse:
--Hair greatly expands the time window for the detection of an illicit drug.
Urinalysis of a single specimen generally can detect the presence of drugs
for a period of several days to a week or two, depending on the drug. Hair
analysis can detect drug use for several months or more, depending on the
length of the hair.
--Brief periods of abstinence from drugs will not significantly alter the
outcome of hair analysis.
--Hair is relatively inert, easy to handle, and requires no special storage
facilities or conditions. Compared with urine samples, it presents fewer
risks of disease transmission.
--Having some hair snipped from the head is less invasive and embarrassing
for most people than supplying a monitored urine specimen.
--Collecting comparable samples for repeat testing is easier with hair than
with urine.
--Contaminating or altering a sample to distort or manipulate test results is
much more difficult with hair than with urine. Preliminary research shows
that even treating hair with a variety of strong compounds will not
completely eliminate traces of illicit drugs.
Scientific basis for hair testing
Scientifically, the radioimmunoassay of hair (RIAH) rests on the fact that
growing hair absorbs drugs and their metabolites into its structure from the
circulatory system. Metabolites are the biochemical products of the breakdown
of drugs within the body. For cocaine, both urine testing and hair testing
detect the drug metabolites rather than the illegal drug itself.(ref. 3)
Once a drug metabolite is embedded in the hair sheath, a process which
appears to occur while the hair is being formed in its follicle, the
metabolite is very nearly permanent. As the hair shaft grows, it forms a
longitudinal record of the compounds it has absorbed, including drugs of
abuse.
Drug metabolites appear in detectable levels in hair approximately a week
after ingestion.(ref. 4) Hair grows at an average rate of about half an inch
every 30 days. The hair shaft can be cut into various lengths, allowing a
"time line" analysis of drug consumption. Like a tape recording, a hair
specimen can allow an analyst to construct a history of drug use This "tape
recording" presents an expanded time-monitoring window in contrast to single
urine specimens collected at widely spaced intervals.
Additional research is needed to better understand such issues as the
biochemical processes of the absorption of drugs and their metabolites into
hair, dose-related cutoff levels, and the influence of external
contamination. NIJ is currently conducting studies on these issues.
The Pinellas County project
Pinellas County (population 851,000), located on Florida's West Central
coast, is the most highly urbanized and densely populated county in Florida.
In fall 1989, officials from a local drug treatment provider (Operation PAR),
the Pinellas County Sheriff's Office, and a researcher from the University of
South Florida conducted a research project to (1) compare the results of hair
testing, urinalysis, and self-reports of drug use among arrestees at the
Pinellas County Jail, and (2) evaluate the implementation and utility of a
hair-based drug monitoring system.
Funded by NIJ and the Pinellas County Sherrif's Department, the project was
similar to NIJ's DUF program. and the method was essentially the same. Recent
arrestees agreed to anonymous interviews and were tested for evidence of
recent drug use. Using a modified DUF questionnaire, the project gathered
self-reported drug-use data. Urine specimens were collected and analyzed. The
research staff also collected hair samples from the arrestees and had those
samples tested, using RIAH technology.
Between 250 and 300 arrestees who met the general eligibility conditions of
the national DUF protocol were interviewed at the time of booking. Anyone
arrested more than 24 hours before contact with the interviewer was excluded
from the sample. In Pinellas, drug arrests constituted about 23 percent of
the sample. Pinellas also included offenders brought in on drunk driving
charges (DUI or DWI).
Findings
The data show that the number of arrests who self-reported they used cocaine
or opiates within the past 30 days was not much greater than those who
reported use within the past 48 hours. Both hair testing and urinalysis
produced a larger number of positive results than did self-reports: more
significantly, however, there was a substantially greater proportion of
positive hair assays than positive urine samples [*Note: This finding must be
qualified. The hair samples were not assayed for marijuana because not enough
hair was obtained to conduct assays for all desired tests.]
Overall, the findings are consistent with the literature of recent years
correlating self-reported drug use and the outcome of urine testing for drugs
of abuse. One consistently finds patterns among arrests of underreporting of
personal drug use. Other main findings can be summarized as follows:
--There were about four times more positive hair test results for cocaine
than for self-reported use within the previous 30 days (46.5 percent vs. 11.2
percent).
--There were more than twice the number of positive hair test results for
cocaine than positive urine tests (46.5 percent vs. 20.4 percent).
--There were 5 1/2 times more positive hair test results for cocaine than for
self-reported use within the previous 48 hours (46.5 percent vs. 8.3
percent).
--There were 2 1/2 times more positive urine test results for cocaine than
for self-reported use within the previous 48 hours (20.4 percent vs. 8.3
percent).
--There were nearly nine times more positive hair test results for opiates
than for self-reported use within the previous 30 days (8.9 percent vs. 1
percent).
The outcomes for self-reports and one-time urinalysis testing display a clear
pattern of underreporting. However, comparing urinalysis results to
self-reported use within the previous 30 days reveals a relatively smaller
amount of discrepancy.
In addition to urinalysis testing conducted by EMIT (trademark) (enzyme
multiplied immunoassay technique), urinalysis was conducted by a second
method, fluorescence polarization immunoassay (FPIA).
A total of 256 specimens were analyzed by radioimmunoassay of hair, and by
EMIT and FPIA for urine. Of these, 153 had the same test result, whether
positive or negative, when tested by RIAH, EMIT, and FPIA. The most important
result is that 88 of the 256 specimens analyzed for opiates and cocaine were
identified as drug positive by RIAH but negative by both urine testing
techniques.
Of these 88 specimens, confirmatory testing was completed on 9 (10 percent)
using a very accurate but expensive technique: gas chromatography/mass
spectrometry (GC/MS). Budgetary constraints and hair specimen sizes precluded
further confirmation tests. However, even though these tests used only the
remaining portions of the hair samples, GC/MS detected cocaine in all nine
specimens, indicating RlAH's potential to identify individuals who may be
drug users but who probably have not taken drugs within a day or two of a
urine test.
Seven specimens were positive by RIAH as well as by one of the two urine test
methods. This difference is probably due to one of the urine tests being a
"false-negative" result; that is, the drug metabolite was not present in
sufficient quantity to be reliably identified as a drug-positive specimen.
Two specimens were negative by RIAH and negative on one of the urine tests
but positive on another. This indicates a "false positive" urine result; that
is, the test result is reported as positive even though a drug metabolite is
not truly present.* [*Note: The data most difficult to explain are those that
show 6 of 256 specimens (2.4 percent) negative by RIAH but positive by both
urine test methods. While there are several possible explanations, including
the possibility that these were casual users, additional research is needed
to explore the anomaly.]
Quantitative analysis
The laboratory that tested the hair samples developed a tentative scale that
categorizes specimen results into six groups based on the level of drug
detected. In this "Psychemedics Scale," Group 1 RIAH results are the lowest
detected level of an assayed drug, while Group 6 is the highest level. Group
0, no drug detected, is not reported here.
At low levels of cocaine use (Groups 1 and 2), RIAH appears to detect about
10 times as many drug users as urinalysis, based on currently accepted cutoff
levels. Thus, a single hair test appears to have the potential of identifying
many more drug users than would otherwise become known by a single urine
screen.
At comparable levels, urinalysis techniques cannot differentiate between
users who have recently consumed very small amounts of a drug and those who
have consumed significant amounts but have had a more than 2- or 3-day lapse
between ingestion and testing.
At moderate levels of cocaine use (Groups 3 and 4), RIAH appears to detect
three to four times as many users as urinalysis. As the intensity of cocaine
use rises, RIAH and FPIA urinalysis values come into close alignment, with
negligible differences between them. This makes intuitive sense. Daily or
near-daily users would likely be detected by any assay method, inasmuch as
such users are virtually always excreting the drug or its metabolites.
Among the criteria used by the laboratory to assign each specimen an
intensity-of-use scale number, the staff included judgments that reflected
the extent to which the hair sample had been previously treated by commercial
hair products. For this reason, the group numbers assigned reflect not only
rigid cutoffs in nanograms per 10 milligrams of hair, but also the clinical
judgments of the laboratory staff.
Conclusions
Radioimmunoassay of a single hair specimen detects more drug exposure than is
self-reported or detected by a single urine test. The degree of this
underreporting appears to vary to some extent with the type of drug. These
research findings are most relevant for cocaine: It was detected in a
relatively large number of subjects. and three disparate types of data --
self-report, urinalysis, and RIAH -- were available. Although more work must
be done in establishing standard protocols and procedures for using RIAH as a
routine screening device. sufficient information is available to support the
utility of hair testing for detecting drugs of abuse.
Hair testing appears to have a number of advantages, including its less
invasive method of collection, the extended time window of results, the
stability of the medium, and the difficulty of tampering with the medium to
evade positive test results. Some practical difficulties may occur in
collecting specimens from individuals with short or no head hair.
RlAH's applicability in the monitoring of offender drug use may very likely
permit a better determination of drug exposure over longer timeframes than is
currently available using urine screening methods conducted less than twice a
week. In fact, hair-based testing could be conducted with less frequency than
would be required in order to achieve a comparable level of confidence with
urinalysis testing.
Finally, hair testing appears to hold promise as a useful tool in drug
epidemiology. Yet, a substantial amount of field testing is still required
before it attains the degree of acceptance now accorded urinalysis testing.
Nevertheless, the outcome of this project indicates that such testing ought
to continue.
Notes
1. E.D. Wish and B. Gropper, 1990. "Drug testing by the criminal justice
system." In Drugs and Crime, ed. Michael Tonry and James Q. Wilson, vol. 13
of Crime and Justice: A Review of Research. Chicago, University of Chicago
Press.
2. T. Mieczkowski, 1990. "The accuracy of self-reported drug use: An analysis
of new data." In Drugs, Crime and the Criminal Justice System, ed. R.
Weisheit, Cincinnati, Ohio, Anderson.
3. W. Baumgartner, V. Hill, and W. Blahd, 1989. "Hair analysis for drugs of
abuse." Journal of Forensic Sciences 34, 6: 1433-53.
4. E. Cone, 1990. "Testing human hair for drugs of abuse: Individual dose and
time profiles of morphine and codeine in plasma, saliva, urine, and beard
compared to drug-induced effects on pupils and behavior." Journal of American
Toxicology 14:1-7.
5. Mieczkowski, n. 2 above.
Tom Mieczkowsi, Ph.D., is an assistant professor of criminology at the
University of South Florida. Associated in this research were three officials
of Operation PAR, Inc., a St. Petersburg drug treatment provider whose name
stands for "Parental Awareness and Responsibility." Harvey J. Landress, ACSW,
is deputy director for planning and development, Richard Newel is a program
evaluator, and Shirley D. Coletti is president of Operation PAR.
Opinions or points of view expressed in this document are those of the
authors and do not necessarily reflect the official position or policies of
the U.S. Department of Justice.
The National Institute of Justice is a component of the Office of Justice
Programs, which also includes the Bureau of Justice Assistance, Office of
Juvenile Justice and Delinquency Prevention, and the Office for Victims of
Crime.
NCJ 138539
[Note: The published report from which this information was input contains
accompanying charts and tables.]